Method and apparatus for coating a product

ABSTRACT

There is described an apparatus ( 1 ) that may be used for providing ice lollies ( 2 ) with a coating from a dipping container ( 4 ). The coating mix ( 3 ) comprises almond flakes ( 16 ) and fluid chocolate ( 10 ) which is inserted in a third area ( 38 ). Displacement bodies ( 25 ) are lifted and lowered into first areas ( 28 ) while the ice lolly ( 2 ) is lowered in a central second area ( 20 ). The lowering occurs when the displacement means are completely down whereby a well-defined surface level ( 23 ) is achieved by using level plates ( 21 ). The movement of the displacement means ( 25 ) creates sufficient stirring and flow in flow ducts ( 36, 43 ) in order to ensure homogenisation of the coating mix ( 3 ) situated in the central second area ( 20 ) where the ice lollies ( 2 ) are coated.

This application claims the benefit of Danish Application No. PA 199901441 filed Oct. 8, 1999 and International Application No.PCT/DK00/00555 filed Oct. 5, 2000.

BACKGROUND OF THE INVENTION

The present invention concerns a method for coating a product with afluid coating containing solid fragile additives as the product isdipped in the coating mix which is stirred for preventing sedimentationof the additives.

Furthermore, the invention concerns an apparatus for use with suchcoating, the apparatus comprising a container, stirring means and supplymeans for the coating and the additives.

The invention particularly finds application by coating of confectioneryproducts like ice lollies with fluid chocolate coating containing nutpieces, preferably elongate almond flakes. The products may alsocomprise inedible products, for example files provided withgrinding/filing particles which are mixed into fluid glue acting ascoating on a base element in the file. Also, in corresponding way theinvention will find application within other areas where coating isestablished by dipping a product in a coating mix in which stirring isperformed for avoiding sedimentation of different fluid elements in thecoating. Thus the present invention may also be used with advantage inconnection with a coating consisting of different fluid basic componentswhich have a tendency toward sedimentation if stirring is not performed,and where the individual basic components may be decomposed by pumping.Even though additives are used to designate particle-shaped objects inthe present application, the expression may also cover a fluid additive,which is fragile, as there is a risk of decomposition by strongmechanical influence through pumping and/or stirring.

Previously, when establishing chocolate coating containing fragileadditives, containers in which the ice lollies were dipped by rows havebeen used as they are freely suspended at the underside of a traditionalslat belt conveyor. In the conveyor, displacement pumps of differenttypes have been used for creating stirring in the form of circulation inthe fluid chocolate mass containing the almond flakes. This has oftenbeen combined with a rotating mechanical agitator placed at the bottomof the container in order to create sufficient movement in the coatingmix.

However, the prior art methods for creating movement in the coating mixhave implied a problem as the displacement pumps and the stirring meanshave had a destroying effect on the fragile additives, as for examplealmond flakes, nut pieces or similar. It is perceived as a quality inthe finished product that such additives maintains the originallyintended size, and thus it has been unfavourable when such additiveswere crushed in connection with the stirring.

Furthermore, the prior art vessels have been disadvantageous as therehas been a need for mixing chocolate mass and additives in advance. Thishas caused the additives to have long keeping time in the chocolatemass. This has caused a quality problem as almond flakes, when mixedinto the warm chocolate mass typically having a temperature of 25–40°C., will be warmed up. Hereby oil is liberated which decomposes thechocolate mass.

In order to achieve sufficient homogeneity and uniformity in the coatingmix, it has been necessary to work with relatively large amounts ofcoating mix for covering the consumption occurring by dipping theproducts. This has been unfavourable by shutting down the process as arelatively large amount of coating mix has to be discarded. Furthermore,a large amount of coating mix will result in some nut pieces staying along time in the mixture, thereby increasing the risk of liberating oil.

By prior art coating containers used in coating ice lollies, one hasfurthermore had a problem if an ice has been released from a conveyorand is fallen down into the coating mix. Such an ice will cause problemssince the lolly is moved around in the mass. The lolly may be crushed inthe mechanical stirring means and/or crushed in the displacement pumpsused for creating circulation in the coating mix. For many years therehave been experiments with establishing filters and the like forcatching wood splinters. This has, however, been difficult in coatingmixtures containing additives as such additives have to be transportedfreely through the system.

SUMMARY OF THE INVENTION

It is the purpose of the present invention to indicate a method and anapparatus making possible to relieve the drawbacks by the known systemsby enabling a careful handling which is not decomposing the additivesand which simultaneously can be made very compact in order to reduce theamount of mixed coating mass and additives in the dipping container.

This is achieved according to the present invention by a method of thekind mentioned in the introduction which is peculiar in that thestirring is established as displacing bodies are lifted and lowered inone or more first areas of the coating mix, and that the products arelowered into a second area of the coating mix as the level of thesurface of the coating is kept stationary during the lowering.

The apparatus according to the present invention is peculiar in that thecontainer comprises:

-   -   at least a first area where displacement means are provided and        arranged for moving down into and up from the mix,    -   a second area in which there may be established a well-defined        level for the surface by means of height adjustable level plates        delimiting the second area and in which the products are dipped,        and    -   at least a third area in which supply means discharge, and that        flow connections are established between the areas of the        container.

A system according to the present invention is thus a pump-free systemenabling a very careful handling of the coating mixture. Hereby the riskof damaging the structure of the additives is eliminated. Surprisingly,it has appeared possible to establish sufficient stirring in order toavoid sedimentation/settlement by lifting and lowering the displacementbodies in the coating mix in the dipping container. By lowering thebodies, coating mix is displaced from the first areas of the container.The displaced amount is moved over into the first and third area in thecontainer. By lifting displacement bodies, the coating mix will againrun back to the first areas. This alternating flow together with thedisturbance established in the container has appeared to be sufficientto avoid sedimentation and sufficient for maintaining a homogenousmixture even when using relative small amounts of coating mixture in thedipping container. By moving the displacement bodies, the flow will beestablished through the flow connections between the different areas ofthe container.

By the careful stirring provided by lifting and lowering of thedisplacement bodies, there is not only achieved the advantage ofmaintaining the additives without crushing. At the same time, theproblem with possible ice lollies in the coating mix is solved. Such icelollies will also be treated carefully, and the risk of wood splinters,that can be transferred to the ice lolly product, is also eliminated.

It has appeared possible to provide supply means supplying fluid coatingand supply means supplying additives directly into the container. Whenit is ensured that these discharge in an area not being in directcontact with the second area in which the products are dipped, it willbe possible to establish sufficient mixing for creating a homogenouscoating mix. This is made possible by the supply means discharging in athird area. Before the coating mix reaches the second area, where it isused for coating the products, the mixture will appear homogenous due tothe movement of the displacement bodies.

As a very small amount of coating mix may be used, the staying time ofthe nut pieces in chocolate will be very short, and therefore the riskof oil liberation is reduced. Thus no depreciation of the quality of thefluid coating, typically a chocolate mass, will occur. The fragileadditives will simultaneously appear without being decomposed. Thusthere is provided a coating mix of high quality.

The apparatus is very simple to design as the need for displacementpumps, stirring means and shaft lead-ins between motors outside thecontainer and mechanical stirring means in the container is avoided. Themovement of the displacement means may be established very simply byconnecting these with drive means extending through the open top of thecontainer. In very large containers, supplementing agitators maypossibly be used, passing through the open top side of the containerfrom above and, for example, extending to the third or second area.

An advantageous embodiment of the method is peculiar in that theproducts are lowered at a time where the displacement bodies arecompletely lowered, and where the level of the coating mix surface iskept stationary at an upper level. In this way it is ensured that theproducts are imparted coating to a uniform height. This level isachieved in a particularly precise and simple way by using heightadjustable level plates in the apparatus. The level plates may beadjusted in the desired height. By lowering the displacement bodies, thecoating mix in the second area of the container will run over the edgeof the level plates.

Alternatively, it will be possible to operate with two sets of levelplates so that there is a first set of level plates delimiting thesecond area, and that within this area there is provided a further setof level plates for fine adjustment of the level of the coating. Thisoccurs as these plates are provided with small mutual distance largelycorresponding to the width of the product which is dipped into thecoating mix.

Usually, the adjustable level plates will be placed stationarily in thesecond area when the apparatus is used for a certain type of products.When the apparatus is used for a second product, the level plates may beadjusted for fitting to such a new product.

Even though the level in the container is adjusted by using the levelplates, it will be possible to replenish the container. For thispurpose, the method according to the invention is peculiar in that theconsumption of the coating mix is determined, and that replenishment ofcoating and additives is performed in an adjusted proportion inconsequence of this determination as the additives and fluid coating areinserted in a third area of the coating mix. For registering theconsumption there is provided means which registers the level in thecontainer. These may be optical means or acoustic means with atransmitter/receiver function. They may also be based on pressuresensors where a pressure is transformed to a surface level in thecontainer. In such pressure sensors, there may be attained a precisionin consumption within 1–2 decilitres coating mix by measurements inmicrobar.

As mentioned previously, it is essential that the supply means dischargein the third area in order to achieve sufficient mixing. Mixing of theadditives in the fluid coating occurs in the third area before coatingmixing penetrates into the first area via the flow connections.

It is preferred that coating is inserted by pumping at an arbitrarylevel in the container while the additives are sprinkled down on thesurface of the coating mix located in the third area. Hereby is achieveda very simple transport by means of a vibration supply or by means of aconveyor belt for supplying the additives.

The supply means will preferably be controlled by a control unitreceiving a signal from registration means which measures the level ofthe coating mix in the container. Thus it will be possible currently tosupply the amount of fluid coating and the amount of additives necessaryfor keeping the amount of coating mix within predetermined limits. Theselimits ensure that the coating mix will always reach the top side of thelevel plates when the displacement bodies are completely lowered intothe coating mix.

According to an advantageous embodiment, the apparatus is peculiar inthat the container is elongate, that an elongate first area is disposedat each side of a central second area, that height adjustable levelplates are disposed in the border area between the second area and thefirst areas, that the third area is disposed in continuation of thesecond area, that the displacement means are elongate and largely fillsout the area of an associated first area, that the third area and thesecond area are separated by a dividing plate extending from a levelabove the uppermost possible surface level of the coating mix to a levelbelow the lowermost possible surface level of the coating mix, and thatthe flow connections are formed between the dividing and level platesand the bottom of the container.

With such a design of the apparatus, the displacement bodies will forcethe coating mix under the level plates and the dividing plate bylowering into the coating mix. Hereby is avoided the risk of additivesbeing conveyed into the second area, lying on the surface of the coatingmix. When the container is designed in this way, it will be suitable forplacing under a conveyor where several products, for example iceLollies, are suspended at the underside of a slat conveyor. Thus a largenumber of juxtaposed ice jollies may simultaneously be dipped in theelongate central area. As the third area is disposed along one side ofthe elongate area, a particularly simple locating of the supply meansoutside the product conveyor situated above the container is achieved.

If the upper side of the displacement means is inclined toward thecentral second area and have a lower side edge situated over the levelplates when the displacement means are in their upper position, possiblecoating mix, which during the lowering of the means runs over the upperside of the level plates and is disposed at the upper side of thedisplacement bodies, may run back into the central second area when thedisplacement means subsequently are lifted to their upper position.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained more closely with reference to theaccompanying drawing, where:

FIG. 1 shows a side view partly in section through an embodiment of anapparatus according to the invention,

FIGS. 2–4 show a cross-section through the apparatus of FIG. 1 forillustrating different steps of the method according to the invention,

FIG. 5 shows a view corresponding to FIG. 1 for illustrating a secondembodiment of an apparatus according to the invention, and

FIG. 6 shows a section corresponding to FIG. 3 for illustrating afurther embodiment of the apparatus according to the invention.

Identical or corresponding elements in the Figures of the drawing willbe provided the same designations. Therefore, no specific explanationwill be given to each element in connection with each single Figure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1–4 of the drawing illustrates an apparatus according to theinvention which is intended for use in coating products in the form ofice lollies 2 that are dipped in a coating mix 3 provided in a container4. The container 4 is elongate in direction 5 so that a row of icelollies 2 may be placed side by side above the container 4 and dippedinto the coating mix 3.

The container 4 is connected with a pipeline 6 for supplying fluidchocolate mass. In the pipeline 6 there is provided a control valve 7which may be opened and closed as a result of a signal from a controlunit 8. A pipeline 9 at the other side of the valve 7 is connected witha raw material container (not shown) containing chocolate mass which isheated to a desired temperature. The fluid chocolate mass 10 is thusinserted via the pipeline 6 in an end side 11 of the container 4 at alevel under the surface 12 of the coating mix 3. Hereby splash isavoided.

The apparatus 1 furthermore comprises a conveyor 13 in the shape of aconveyor belt running around reversing wheels 14. One of the reversingwheels are connected with a motor (not shown) which is also connectedwith the control unit 8 and which is started and stopped as a result ofsignals from the control unit 8. The conveyor belt 13 is driven in thedirection of the arrow 15. Hereby almond flakes 16 coming from a storagecontainer (not shown), which is located at the left side of FIG. 1 at aposition besides the container 4, and a conveyor (not shown) used foradvancing the ice lollies 2. The almond flakes 16 are conveyed over thereversing wheel 14 which is situated above the container 3 so that thealmond flakes 16 are sprinkled down on the surface 12. Alternatively,the conveyor may be a vibration conveyor or an inclining funnel whichare known within the art.

The apparatus 1 comprises displacement means 17 arranged to be liftedand lowered in first areas 18 of the coating mix (see FIGS. 2–4). Thefirst areas 18 are provided along side edges 19 on the elongatecontainer and disposed at each side of a central second area 20 which isthe area where the ice lollies 2 are lowered into the coating mix 3.

Between the elongate first area 18 and the central second area 20, thereare provided first level plates 21. These are provided adjustable inheight as they are placed on vertical guides (not shown). In theembodiment shown there is provided second level plates 22 which aredisposed within the first level plates 21 and which are also adjustablein height. The distance between the second level plates 22 issignificantly less in order to provide a well-defined upper surfacelevel 23 therebetween. The distance between the second level plates 22will only be a little greater than the width 24 of an ice lolly which islowered. By using the level plates there is achieved a well-definedsurface level 23 defining the height of the coating to be established onthe ice lolly 2. The way in which the surface level 23 is establishedwill be explained later under the explanation of the mode of operationof the apparatus.

The displacement means 17 comprise elongate displacement means 25 thatlargely fills out the area of an associated first area 18. At each end,the displacement means 25 are connected with a bracket 26 extending upthrough the upper opening 27 of the vessel and which comprises anoutward projecting part 28 ending in a mounting plate 29. The mountingplate 29 is connected with an endless belt 30, preferably toothed belt,running about two reversing wheels 31 which are connected with drivemeans enabling reciprocating movement of the belts 30. Hereby isestablished an up- and down-ward movement 32 of the bracket 26 andthereby the displacement means 25. The driving device comprising theendless belts and the reversing wheels 31 are suitably disposed at eachside of the container 4 so that free passage for the ice lollies 2 ispossible in direction across the vessel in direction as indicated witharrow 33. It is possible to used cylinders to provide the up- anddownward movement 32 instead of the belts 30.

As mentioned above, the first level plates 21 are provided in the areabetween the first areas 18 and the central second area 20. The levelplates 21 do not extend completely to the bottom 34 of the container 4.Between the underside 35 of the level plates and the bottom 34 there isthus provided an interspace 36 providing flow ducts for the passage ofthe coating mix from the first areas 18 to the second area 20. Thecentral part of the container 4 is furthermore provided with a dividingplate 37. The dividing plate 37 delimits the second area 20 from a thirdarea 38 where fluid chocolate mass 10 and almond flakes 16 areintroduced to the container 4. The dividing plate 37 extends from aposition 39 above an upper surface level 23 to a position 41 under alowermost level 42 for the surface 12 of the coating mix. Between thelower edge 41 and the bottom 34 of the container 4, there is thusprovided a flow duct 43 for passage of the coating mix between the thirdarea 38 and the second area 20. Each of the displacement bodies 25 havean upper side 44 inclining down toward the central area 20. By an upperposition of the displacement bodies 25 (shown in FIG. 2), the lower sideedge 45 will be at level with or above an upper side edge 46 of thefirst dividing plates 21. Hereby, possible coating mix 47 (see FIG. 4)situated at the upper side of the displacement bodies 25 will run backinto the central second area 20.

The apparatus comprises a height registering means 48 (see FIG. 1). Thisis provided in the form of a distance measuring sensor which measuresthe distance to the surface 12 in the coating mix in the third area 38where the surface level is identical to the surface level in the secondarea 20. The sensor 48 is connected with the control unit 8 fortransmitting a signal to the latter which is used for activating thevalve 7 and the motors for the conveyor belt 16 for supplying fluidchocolate mass and almond flakes concurrently with consumption occurringwhen the coating mass 3 is drawn up with the ice lollies 2.Alternatively mechanical sensors may be used comprising a float on thesurface of the coating mix in the second or third area 20. 38.

The apparatus 1 is used in a method according to the invention forcoating the ice lollies 2 with the fluid chocolate mass containing thealmond flakes 16. This occurs by dipping the ice lollies 2 in thecoating mix 3 simultaneously with stirring the coating mix for avoidingsedimentation of the almond flakes 16. The stirring is established bylifting and lowering the displacement means 25 while the endless belts30 are moved back and forth. The displacement bodies 25 are thus liftedand lowered in the elongate first areas 18. Hereby the coating mass isbrought through the flow connections 36 and 43 under the level plates 21and the dividing plate 37.

By the reciprocating movement there is performed such a stirring thatthe almond flakes 16 are mixed with the fluid chocolate mass in thethird area 38. Due to the dividing plate 37, almond flakes cannot flowon the surface 12 of the mixture into the second area 20.

Homogenisation of the mixture occurs by pressing/sucking it out into thefirst and second areas by the movement of the displacement bodies. Whenthe displacement bodies are in their upper position as illustrated inFIG. 2, the lowermost level 42 for the coating mix 3 is provided in thesecond area 20. A row of ice lollies 2 is brought into position overarea 20.

In the subsequent step illustrated in FIG. 3, lowering of thedisplacement bodies 25 is initiated. Hereby, the level of the coatingmix rises in the second area. In FIG. 4 is illustrated a situation wherethe displacement bodies 25 are lowered to their lowermost position inthe coating mix 3. There is established such a filling of coating mix 3that the coating will reach the upper side of the first level plates 21and the second level plates 22. Thus a well-defined upper surface level23 is provided. In this step the row of ice jollies 2 are lowered intothe second area 20. The lowering occurs with a well-defined height whichpreferably will be intended by a slat conveyor or similar transportmeans used for advancing the ice lollies 2. A well-defined height of thecoating applied to the ice lollies 2 is thus established.

Then the row of ice lollies 2 is drawn up again from the coating mix 3simultaneously with the displacement bodies 25 being lifted to theirupper position illustrated in FIG. 2.

At a well-defined time in the cycle, the sensor 48 is activated againand measures the distance to the surface 12. If the surface reaches alower limit, the container is replenished as the sensor transmits asignal to the control unit 8 activating the valve 7 and the drive meansfor the conveyor 13.

The apparatus shown in FIG. 5 differs from the embodiment shown in FIG.1 by the position of the pipeline 6 for the supply of fluid chocolatemass. In FIG. 5, the pipeline 6 is disposed for discharging into thethird part 38 of the container at a level above the surface 12 of thecoating mix 3. Even though this may imply risk of splashing, this hasappeared advantageous in practice in connection with certain chocolatemixtures. Hereby is avoided the risk of entrainment of air. It isundesirable to entrain air in the coating mixture as air bubbles hereinmay cause insufficiently covering coating on the ice lolly.

The embodiment of the apparatus shown in FIG. 6 differs from theembodiment shown in FIGS. 1–4 by the other level plates 22 beingomitted. Instead is used a device 49 that may lift and lower the wholecontainer 4. The device 49 may thus provide an up- and downward goingmovement 50 of the container 4. The device 49 may thus be arranged witha spindle/thread connection with a cylinder or other device that mayestablish the up- and downward going movement with the purposed of fineadjustment of the upper well-defined surface level 23 for the surface 12of the coating mix.

By using the device 49, cleaning of the apparatus becomes easier asthere are fewer parts in the container 4 where coating mass may hang on.If the fine adjustment is provided by means of the device 49, the firstlevel plates 21 may be provided in a fixed position. Hereby is achieveda particularly simple and very cleaning friendly structure as thecontainer 4 do not have to be provided with adjusting means, guide andthe like inside.

In the above, the invention has been explained with reference tospecific embodiments and a specific application. However, it will appearthat the apparatus may designed it other ways as well as the method maybe used in connection with other products than ice lollies 2 as set outin the present specification and as defined in the claims. By thelifting and lowering of the displacement bodies in the mass 3, a carefulhandling occurs which does not cause crushing of the almond flakes.Furthermore, the flows established through the flow ducts will establishenough movement in the coating mix for avoiding sedimentation of thealmond flakes 16 or other fragile additives. Instead of almond flakes,nut pieces and raisins or other additives may also be used.

1. A method for coating a product with a fluid coating containing solidfragile additives as the product is dipped in a coating mix which isstirred for preventing sedimentation of the additives, wherein thestirring is established as displacing bodies are lifted and lowered inone or more first areas of the coating mix, and that the products arelowered into a second area of the coating mix as the level of thesurface of the coating is kept stationary during the lowering.
 2. Amethod according to claim 1, wherein the products are lowered at a timewhere the displacement bodies are completely lowered in the coating mix,and where the level of the surface of the coating mix is kept stationaryat an upper level.
 3. A method according to claim 2, wherein thestationary level is defined by height adjustable level plates that areplaced in the second area.
 4. A method according to claim 1, wherein theconsumption of coating mix is determined, and wherein replenishment ofcoating and additives is performed in an adjusted proportion inconsequence of this determination as the additives and fluid coating areinserted in a third area of the coating mix.
 5. A method according toclaim 4, wherein fluid coating is inserted by pumping, and wherein theadditives are sprinkled down on the surface in the third area.
 6. Amethod according to claim 1, wherein the products are constituted by icelollies, and wherein the coating is constituted by a chocolate masscontaining nut pieces.
 7. A method according to claim 6, wherein the nutpieces are elongate almond flakes.